1. Field of the Invention
The present invention relates to the field of container handling apparatus, and in a preferred embodiment to empty and full container handling apparatus as used in the food and beverage industries.
2. Prior Art
The preferred embodiments of the present invention are intended for use in the food and beverage industries for changing position, across the width of a conveyer, of selected containers for such purposes as separating containers which are somehow unsatisfactory from the main line, sorting of containers and the like. Accordingly, only the prior art relating to the food and beverage industry will be discussed herein. Further, the word "container" as used herein is used in a very general sense, whereas the words "bottles" and "cans" are each used in their more natural limiting sense, the latter being used to provide greater specificity to the description of preferred embodiment of the invention. It should be noted however, that the description of the preferred embodiments with respect to bottles and cans is in general directly applicable to containers of substantially all kinds.
In the beverage industry, particularly the soft drink and beer industries, large quantities of empty cans and glass and plastic bottles proceed along a conveyor system through processing steps to obtain properly filled, sealed and labeled product ready for shipment. In this equipment, conveyor speeds on the order of 1000 to 2000 containers per minute are common. By their nature, automatic inspection functions at various positions along this processing line must have associated therewith some method and apparatus for automatically diverting unacceptable containers from the main conveyor line as required.
One general type of container diverter system which has been used in the prior art, and is of the general type used in the present invention, is a system wherein the containers proceed typically adjacent one side of a relatively wide conveyor. Selected containers which are to be diverted are then momentarily contacted from the side to push the same to the other side of the conveyor, the undiverted containers proceeding onto a first outflow conveyor and the diverted containers proceeding to a second outflow conveyor.
One type of actuator which has been used with such systems has been a simple pneumatic actuator, triggered at the appropriate time in a bang-bang fashion to divert selected containers without in any way interfering with the travel of either the prior or the next container, unless of course that one is to be diverted also. Such a diverter is functional, though has certain disadvantages. Because it is preferable to have the diverter reasonably close to the container before it is fired, and typically lines run containers of different size at different times, conversion of the line to a different size container normally requires physical readjustment of the location of the actuator as well as the changing of the spacing of the fences defining the container path to the diverter. Further, adjustments of air pressure, etc. may also be required to accommodate filled containers of different sizes, which thus have different weights. Also, if the container is to be diverted because a prior inspection machine determined it had no cap or seal, the violence of the bang-bang type operation will usually cause spillage of some of the contents, making a mess on the conveyor system. Because such diverters can tend to stick, they must be driven fairly hard, as a minimum, to be sure they will reliably operate.
Also, container diverting systems using compressed air actuators, particularly at high speed, have some tendency to cause a container, particularly a beverage bottle, to turn over, which will let the container roll to undesirable positions across the conveyor, perhaps jam on the fence dividing the two outfeed conveyors, or cause other problems downstream in the equipment if the container successfully negotiates the intended outfeed conveyor.
Another type of diverter currently in use has a series of fingers of different lengths arranged along the conveyor so that the fingers may be extended into the path of a container on the conveyor to define a sort of inclined plane to divert the container to the other side of the conveyor. Since if all fingers were extended at the time, the fingers would span considerably more than the diameter of one container, the fingers must be extended and retracted in a sort of sequential manner so as to not interfere with the possible free travel of adjacent containers, on the assumption that the adjacent containers are likely not intended to be diverted. This system, too, is functional, though is mechanically complex and can require excessive maintenance. Also, actual systems of this type have only partially diverted containers from the main line, depending upon the velocity obtained during that partial diversion to carry a container the rest of the way across the conveyor. This, of course, makes the diversion conveyor-speed dependent, an undesirable characteristic, and because of only a partial positive diversion, will not satisfactorily operate down to zero conveyor speed as required during start up and shut down of the line for maintenance, to clear a problem or for container size change over.
Another container diverter system is disclosed in U.S. Pat. No. 4,501,365. This system is somewhat similar to the foregoing in that the positive part of the container diversion occurs over a longer time than the time of passage of a single container. The same has the further advantage of being able to provide positive diversion for the full container diversion distance desired. However, it too is complex and requires considerable additional space to accommodate the mechanism required.